Ignition light - Intermittent - Cylinder down

Hi guys, like to pick your brains if you don't mind. Fiat Coupe 20V NA. Ignition light been coming on intermittently. Read lots of threads on here on this. I changed out the idle control valve, no difference. Felt injectors and pulled connectors when running to see if I could notice a change. What I have noticed is it tends to come on when hot, from standstill. And when it does come on, I somehow worked out that when you dip the clutch and rev it hard, this put the light out and it drove fine. However lately this trick is not working so much and the light is staying on. Plus the engine is running off a cylinder very badly, especially on start up.

Any ideas? Lambda, injector, coil pack. What do you need to read the fault code? And guess it wouldn't flag up a specific point of error? Car is P reg.

Thanks
Allan

Copied from a post a few threads down...

Probably a failing injector. They tend to fail open circuit when hot, especially when you go back and re-start the engine after it's been sitting there hot for a while.

When you catch it misfiring disconnect each injector in turn to see which one doesn't make any difference to the misfire and that'll be the problem cylinder.

Yes I read that thread and tried that but I'm sure they all seem to make a difference. I'll pull the connectors and check them again.

Thanks.

Did you try it while it was misfiring and injector light on? If so, then it may not be an injector if it made no difference, but could be a coil pack although that wouldn't flag an ECU error.

Yes I tried it when it was misfiring with the light on, made no difference. It seems to do it mostly when it is warm, from start up if it has been sitting in this rare Scottish sun! Also tends to do it randomly when driving, revving the engine to limiter does work sometimes.

Might investigate the coil pack then. Guess plugs could be a possibility too, breaking down when hot.

Coil pack or spark plug is possible but there are no specific error codes for either so they wouldn't light the warning lamp.

If the warning light is coming on with the problem then I'd try to get the codes read before switching out anything else. I have diagnostic kit to read the error codes but probably best to check while the light is on if the problem is intermittent (although some problems are still stored even when the light is out), so may be best to get a set of the cables yourself if you have a laptop to run the startrek software.

Thanks, what cables do I need to plug into the car? Where does it plug in? And the Startrek software, need to purchase it?

You can download the 20v/t Startrek software here:

http://www.nailed-barnacle.co.uk/coupe/startrek/startrek.html

There's also:
http://www.multiecuscan.net/

but you may need the registered version of that to clear codes on the coupe.

You also need a VAG/KKL cable + the 3 pin Fiat adapter, eg. ebay # 281385010219. It plugs into the socket in front of the screen washer bottle.

Note there are known to be various fake VAG/KKL cables around that don't work with the latest FTDI drivers (or at all), the one I linked on ebay is just an example of the correct cables I have no idea if those specific ones actually work on the coupe or not.

Great! Many thanks Graham.

I just checked it again there. Missing on start up, injector light wasn't on that time. I'll replace the plugs first I think, one thing eliminated.